lexical.outStream = new PrintWriter(System.out);

System.out is a predefined PrintStream printing on the console. It is
documented at
http://java.sun.com/j2se/1.4.2/docs/api/java/lang/System.html

Here's an idea - write a Writer subclass that feeds the output to
multiple Writer instances. I've done very little testing. Use at your
own risk:

import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.io.Writer;

/**
 * Write to multiple Writer instances
 *
 */

public class MultiWriter extends Writer {

  private Writer[] writers;

  /**
   * New MultiWriter for specified writers. Note that flush is
   * only done on explicit call.
   */
  public MultiWriter(Writer... writers) {
    this.writers = new Writer[writers.length];
    for (int i = 0; i < writers.length; i++) {
      this.writers[i] = writers[i];
    }
  }

  @Override
  public void write(char[] cbuf, int off, int len)
      throws IOException {
    for (Writer w : writers) {
      w.write(cbuf, off, len);
      w.flush();
    }
  }

  @Override
  public void flush() throws IOException {
    for (Writer w : writers) {
      w.flush();
    }
  }

  @Override
  public void close() throws IOException {
    for (Writer w : writers) {
      w.close();
    }
  }

  public static void main(String[] args) throws IOException {
    Writer console = new OutputStreamWriter(System.out);
    Writer file = new FileWriter("Testfile.txt");

    Writer dup = new MultiWriter(console, file);
    PrintWriter print = new PrintWriter(dup);

    print.printf("Hello, world");
    print.println();
  }
}